Organic electroluminescence generating devices are typically fabricated by sandwiching one or more organic layers between conductive electrodes. Upon application of an electric field, negative charges are injected into the organic layer or organic layers from one electrode, and positive charges are injected into the organic layer or organic layers from the other electrode. Injected charges travel across the organic layer or organic layers until when they radiatively recombine to emit light.
Examples of prior art organic electroluminescence generating devices are vertical stacks of organic layers sandwiched between two electrodes as illustrated in FIG. 1. An alternate example of prior art organic electroluminescence generating devices comprises three electrode devices where conductive electrodes injecting negative and positive charges into the organic layers are vertically displaced and separated by one or more organic layers. Injected charges travel across the vertical stack of organic layers until they radiatively recombine to emit light. An illustrative example of such structure is shown in FIG. 2.
The vertical displacement of the charge injecting electrodes requires that charge carriers travel across organic layers thereby limiting charge carriers mobility. It is known in the art that charge carrier mobilities in most organic thin films are significantly higher in a plane parallel to the substrate than in a direction perpendicular to the substrate, when these planes correspond to deposited organic layers.